Automatic balancing system for cleaning machine cylinders



Dec. 19, 1950 1.. M. KAHN ETAL 2,534,269

- AUTOMATIC BALANCING SYSTEM FOR CLEANING MACHINE CYLINDERS Filed llay 26, 1948 9 Sheets-Sheet 1 I mJi/(Q,

ATTORNEY Dec. 19, 1950 L. M. KAHN ETAL 2,534,259

AUTOMATIC BALANCING SYSTEM FUR cusmmc mcnm: CYLINDERS Filed May 25, 194 9 Sheets-Sheet 2 FIG.2

ATTORNEY Dec. 19, 1950 L M. KAHN ETAL AUTOMA'fIC BALANCING SYSTEM FOR CLEANING MACHINE CYLINDERS Filed May 26, 1948 S Sheets-Sheet 3 ATTORNEY Dec. 19, 1950 M. KAHN ETAL 2,534,269

'AUTOMATIC BALANCING SYSTEM FOR cwmmc mourns CYLINDERS. Filed May 26, 1948 9 Sheets-Sheet 4 ATTORNEY Dec. 19, 1950 Filed Ma 2a. 1948 3" PHASE L. M. KAHN ET AL AUTOMATIC BALANCING SYSTEM FOR CLEANING MACHINE CYLINDERS 9 Sheets-Sheet 5 ATTORNEY Dec. 19, 1950 L. M. KAHN ETAL 2,534,269

AUTOMATIC BALANCING SYSTEM F01;

CLEANING MACHINE CYLINDERS Filed May 26, 1948 9 Sheets-Sheet 6 I26 Y W. 1

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' IIFIRING! I VOLTAGE g no INVENTORS V m w my, 4/61; {diam/p ATTORN E-Y Dec. 19, 1950 Filed May 26, 1948 L. M. KAHN ET AL AUTOMATIC BALANCING SYSTEM FOR CLEANING MACHINE CYLINDERS S Sheets-Sheet 7 IFIGJO FIG. ll

INVE OR avm 2.1 ka'w flank.

ATTOR NEY Dec. 19, 1950 L.. M. KAHN ETAL 2,534,269

AU'l'DI-ATIC BALANCING SYSTEI FOR CLEANING IACHINE CYLINDERS Filed lay 26, 1948 9 Sheets-Sheet B I VENTOR affa P2 at 6 0/")(KL4IW ATTORNEY Dec. 19, 1950 L. AUTOMATIC BALANCING SYSTEM F0! CLEANING MACHINE CYLINDERS M KAHN ETAL 2,534,269

Filed May 26, 1948 '9 Sheefc-Sheet 9 FIG.I6 m I I L 1' Him. 7'

mill! mu I I ATTORNEY Patented Dec. 19, 1950 AUTOMATIC BALANCING SYSTEM FOR CLEANING MACHINE CYLINDER Leo M. Kahn and Edwin Ellner, New Yorl N. Y.; said Ellner assignor to said Kahn Application May 2a, 1948, Serial No. 29 376 (or. u-svs) 43 Claims.

This invention relates to damp drying systems for laundered or otherwise cleaned articles wherein the extraction of the washing or other cleaning fluid from the articles is eiiected through high speed rotation of a cylinder which is perforated or otherwise provided with fluid extraction and discharge means.

It is well understood that the degree of drying of articles in machines of the above nature depends upon the extent of the centrifugal force produced by high speed rotation of the cylinder so as to eject the fluid from the articles. However, articles oi wet clothing, from their very nature, are generally unsymmetrically distributed in the cylinder, particularly when the cylinder rotates about a horizontal axis, and such undesirable weight distribution produces severe vibrations in the rotating cylinder which impose a limit upon the speed of rotation and adversely affect the degree and time of drying in addition to being potentially injurious to the machine. In practice, most cleaning establishments have found it necessary to divide a cylinder into radial chambers by using partitions and weighing the articles put into each chamber in order to secure initial balance prior to high speed rotation. It is evident that such a practice 'is time consuming and laborious and furthermore does not anticipate changes in weight distribution as the extraction of fluid proceeds to completion. Many establishmcnts which dispense with such precautions are required to be on substantially constant guard to avoid excessive vibration and consequent danger.

In the forms shown herein, a cylinder is provided with peripherally disposed pockets to which are selectively and automatically applied, by elec trical controls, counterbalancing fluids in such a manner as to neutralize the efiect of improper weight distribution within the cylinder. Accordingly. the instant application has as an object thereof, means to establish or identify the portion of the cylinder in which an overweight occurs and the automatic disposition of fluid material to neutralize such overweight and secure a satisfactory rotating or running balance as the extracting process continues to completion, the apparatus being further designed to continue the application or other disposition of counterbalance fluid in'respect to an indicated pocket notwithstanding continued rotation of the cylinder. Such continuity of application embodies many advantages such as will be set forth hereinafter.

Another object of this invention is to provide a series of anguiarly spaced peripheral pockets on a cleaning mat hine cylinder or extractor, and including rotatir g fluid feeding rings, each of the rings being an anged to feed fluid to the respective pockets an ibeing so formed as to concentrate fluid injected t ierein into a position where it may be most efl'ecti rely piped to the pockets. In this connection, ad- 'antage is taken of the rotation of the cylinder an id the ensuing generation of centrifugal forces to direct the counterbalance fluid into a specific ;ite i or piping it to the pockets, as above describe( 1. The pockets are further formed as to eifectively retain fluid during the extraction period and to iutomatically and inherently discharge it when the speed of rotation decreases suillciently.

Another obje at of this invention is to provide a washing mach:ne or other type of cleaning ap paratus wherein counterbalancing fluid is electrically dlrectei to peripherally disposed chambers or pockets )f a horizontal cylinder as required by a. specific state of unbalance, the apparatus being designed tc effectively feed a plurality of revolving ockets or chambers simultaneously if required to securi the running balance, the apparatus being furthi :r arranged to automatically dump or eject the counterbalance fluid when any one cycle of operations has been completed and without interfering with the normal cleaning and damp drying flJ notions of the machine Still another object of this invention is to provide a horizont illy rotating cylinder of elongated form wherein the balancing apparatus of the above general (escription is applied to both ends of the cylinder independently so that the counterbalancing op erations may serve both the static and dynamic balance conditions of the rotating cylinder.

A further object of this invention is to provide an electrical p ck-up device of either the selfgenerating or Sl litch type as hereinafter disclosed, for establishing the existence of a state of unbalance in a roi ating cylinder by determining the vibration there if, the device being mounted on the apparatus (r on the cylinder itself and being responsive to v: ,riations of vibration forces along the cylinder or shaft thereof instead of to vibrations of the apparatus relative to its floor or like support. It has been found that such disposition is highly eifecti' e in that it is less sensitive to extraneous shock. or stimulation.

Other and mast important objects of this invention include the provision of a simple electrical circuit for achiaving all of the foregoing objectives, the provision of means for avoiding undue wear on valves, relays and the like, and the re- 3 quired accomplishment of a state fore the machine enters into its of operation.

The invention is generally applicable to household or commercial washing or extracting machines as well as dry cleaning machines or the like. Whereas washing machines employ water as the cleaning medium, such dry cleaning machines generally employ organic solvents which are usually volatile.

Other objects of my invention will become apparent from the following description of the disclosed form of the invention.

Referring to the drawings:

Fig. 1 is a side view, partly broken away, of one form of the apparatus of the instant invention.

Fig. 2 is a cross-sectional view along the lines 2-2 of Fig. 1 and including a conventional type of electrical vibration pick-up device.

Fig. 3 is a fragmentary front view of three balancing control valves and piping therefor.

Fig. 4 is a schematic diagram of the electrical or electronic circuit.

Fig. 5 is a schematic diagram of the motor control circuit as used in conjunction with the circuit of Fig. 4.

Fig. 5A shows a slight modification of that portion of the motor control circuit that includes the master control valve.

Fig. 5B is a schematic diagram of a further modified motor control circuit showing alternative control of the master valve and a by-pass valve.

Fig. 6 is a graphical view illustrating the operation of the electrical circuit.

Fig. 7 is a longitudinal cross-sectional view of a modified embodiment.

Fig. 8 is a cross-section view along the lines 88 of Fig. 'I.

Fig. 9 is a fragmentary view of a modification of the fluid feeding system disclosed in Fig. 7.

Fig. 10 is a top fragmentary view of a pick-up device which is of particular utility in connection with the foregoinng bflancing apparatus.

Fig. 11 is a side elevational view of the device of Fig. 10.

Fig. 12 is a view similar to Fig. 1 but illustrating a modified form of fluid piping system as well as a modified form of pick-up device.

Fig. 13 is a view along the lines l3l3 of Fig. 12-

Fig. 14 is a modified embodiment of the electrical circuit, such modified embodiment eliminating the electronic tube elements of Fig. 4.

of balance behighest speeds Fig. 15 is a schematic view of a modification of the hold-over circuit.

Fig. 16 is a view similar to Fig. 1 but illustrating a composite apparatus particularly useful for dry-cleaning systems employing organic fluid solvents or the like such as are commerciall used in the dry-cleaning industry, and including a modification in the fluid feeding system.

Referring to Fig. i, the apparatus in the form shown, includes a cylinder I! wherein wet clothes or other articles may be damp dried through centrifugal extraction. The cylinder or drum [1 is supported or driven at one end thereof, the embodiment here shown being generally referred to as a rigid bearing, single end supported machine. This is to be distinguished from a yieldable bearing for permitting free cylinder oscillation. Driving power for the cylinder originates in electric motor I! which may be driven at a low speed for tumbling of the articles in the cylinder and at a high speed for the centrifugal extraction of fluid from the cleaned article-1. This sequence of actions is that which obtains when the machine is either a complete laundry or dry cleaning apparatus. If the apparatus used for extraction alone, as is well known, the two speeds of operation may be modified depending upon the particular type of machine. The pulleys and belts illustrated may serve to transmit the driving power to the main shaft I! so that the cylinder is rotated pursuant to the controlled speed of motor it. As is well known in the laundry or dry cleaning type of apparatus, the various operations may be electrically controlled through a time cycle mechanism wherein the application of water or other cleaning fluid. and the commencement of tumbling or cleaning speed rotation, rinsing, extraction, etc., are automatically performed. Such mechanism being common and well understood in the art, is not here illustrated. Briefly, the cycle generally commences by introducing water or other cleaning fluid into the stationary shell or tub which contains the rotatable cylinder II. A water level control may serve to fill the shell about onethird of its height whereupon the washing or tumbling operation may commence, detergent or other cleaning substance having first been applied.

In the machines having vertical cylinders, the tumbling means will take some other form, as for example, an agitator or the like. At the conclusion of the washing operation, a dump valve in the shell is opened and the dirty wash water 1.- released, whereup the dump valve may be close-1 and a rinsing operation may follow. Following this, the dump valve is again opened, the rotetion speed of the cylinder is greatly increased. and the centrifugal extraction operation commences. The cylinder may either be perforated or may have some other conventional means to discharge or receive the washing fluid.

In laundry systems the fluid is dumped as waste but for so-called dry cleaning systems, the organic cleanin fluid, with or without a. soap ingredient, is filtered, and re-used. As an extractor, substantially only the higher speeds may generally be used. In conjunction with the invention disclosed, we contemplate the use of a balancing system eifectuated through counterbalance fiuid of the same nature as that employed for the cleaning operation so that they may mix and share common paths of flow. In general, the balancing system disclosed offers the practical realization of extremely high speeds of cylinder rotation permitting, for example, a

horizontal cylinder to damp dry at new orders of effectiveness while being available as a horizontal washer. This combination of functions has been long desired by the industry.

Cylinder 20 is arranged to receive, wash and damp-dry clothes in the interior thereof and ribs 2|, 22 and 23 may be provided to assist in the washing function. According to the herein illustrated embodiment of the instant invention,

the ribs are made hollow with solid or enclosed rear end walls and are also employed as pockets or chamber elements for receiving weight counterbalance fluid as will be hereinafter described, although it will be evident that they may serve purely as fluid receiving pockets without participating in the washing function. The pockets are angularly and equally spaced around the periphery of the cylinder so as to effectively divide it into three weight receiving portions degrees apart although it is evident that four or even more ribs or pockets may be employed and spaced apart accordingly.

It is further evident that the pockets may be formed on the outside, rather than the inside of the cylinder, and, if desired, conventional inside ribs may be used for the agitating or clothes lifting function. Such an expedient is illustrated in our prior application, Serial No. 673,680, filed May 31, 1946, and in such case the washing ribs may be perforated or the like as is well known, such rib construction being often considered of advantage for washing purposes.

Means are provided to feed water or other counterbalance fluid from a, tank 25 to the pockets when required by a condition of unbalance. Electrically controlled feed valves 28, 21 and 28 are provided for this purpose, the operation and control of which will be hereinafter described, although each of the feed valves may be replaced by individual and similarly controlled fluid pumps. Assuming that the valves are acuated as required, the fluid flows through the feed pipes 29, 30 and 3| and to the upwardly operating jets 32, 33 and 34. It will be understood that either one or two of such feed pipes will operate at any one time in order to correct a condition of unbalance.

Assuming now that valve 26 has caused the fluid to flow through pipe 29, such fluid will flow through jet or nozzle 32 and into the feed ring 3.5. Feed ring 35 is arranged to feed the fluid through pipe 36 into pocket 2|, while feed rings 31 and 38 are arranged to feed pockets 22 and 23 respectively through the pipes 39 and In respectively.

The feed rings are channel or U-shaped in cross-section and are open along their entire annular floors so as to have an endless inlet. The feed rings together may form a unitary subassembly as by being welded together in the relationship illustrated. Such sub-assembly is made fat to the cylinder so as to rotate therewith, by tack welding, or otherwise securing the side wall 4| of feed ring 38 to radiating ribs 42 which are themselves secured to cylinder end wall 43. The feed rings are disposed about hub 44 of shaft I 9 and each in angularly spaced eccentric relation thereto for purposes which will hereinafter be made clear although it is to be understood that such disposition is not essential, as will be described.

When, for example, fluid is applied through jet 32 to the open annular floor of feed ring 35, centrifugal force will direct and maintain such fluid adjacent the periphery of the feed ring notwithstanding the fact that each i'eed ring is open at its center and annular floor. As jet 32 injects the fluid into feed ring during rotation of the cylinder, such fluid is forced through pipe 36 and into the upper portion of pocket 2| which is closed by end wall 45, the bottom of the pocket being open at 46, thus serving as a discharge outlet for the pocket as will hereinafter appear.

The feed rings are shaped and connected so as to rotate eccentrically with respect to shaft l9 and are formed with discharge openings 35a at the furthest point of eccentricity. Such disposition insures that the opening 35a is always at the furthest distance from the shaft relative to any other point within feed ring 38. Accordingly, when fluid is injected into the open channel of feed ring 35, centrifugal forces generated by the rotation of feed ring 35, cause thefluidto collect adjacentopmingaaso as to be more effectively fed or firm! through pipe 36. In fact. such force is sexually sufllcient to impel the fluid a oonsidembledistanoe so that the expedien; of directing the 1mm point 01 a feed ring tiward its associated pocket may be desirable bui not necessary.

It will be e ident that jets 32, 33 and 34 do not rotate but e: :tend into the shell Iran the stationary pipe; 29 to 3i which traverse opening 41a of sh :11 58a. Fluid flowing Iran the jets will be collec ted in any position of the rotating feed rings at d such fluid collected by the rings will be directed toward the regrecfive outlets. Feed rings 3! and 38 are likewise eccentrically disposed and heir be angularly spaced de grees apart frun and: other to correspond to th pocket disposifim The provision of the feed rings, shaped and dispmed to take advantage of centrifugal [arm makm possible a faster and more positive distillation of the counterbalanwa fluid so as to adiieve such distribution in :hort order and to keep pace with the changing weight as the fluid is extracted frc m the articles. It has been de termined tha; in the absence of unployment of positive force; the injected fluid tm to spread along the int er periphery of the rings and the accomplishment of balance is grmfly and perhaps intoleradly delayed because the fluid feeds too slowly to the weight receiving elements or pockets.

As pocket 2 fills with fluid inizudnced through pipe 36, such fluid is maintained along the inner peripheral Sill face of the pocket pursuant to centrifugal force, The fluid may accumulate as far down as the h wet edge of end wall 45 whereupon it will enter t1". e stationary shell or tub [I through opening 46 (f the pocket 2|. However, the pockets will lse of such size as to accommodate any encounte'able degree of unbalance within the intended operation of the machine as hereinafter set for vh. Accordingly, the injeeted counterbalance fiui (1 will be retained bywall 15 during the extraction operationv At the termination of such operation, and when the speed of cylinder rotation decre: LSGS sufiiciently, the counterbalance fiuid will rapic' ly discharge outside of the cylinder through openi 1g 46 in preparation for a succeeding operation. It can be seen, therefore. that by relying on ce otrifugal forces to maintain the fluid as injectr d. the discharge may be facilitated and its requir 2d duration materially decreased. It will further be observed that the liner in of the pocket 2| is inclined toward the discharge opening 46 so 1 3 to more efi'ecfively discharge the fluid therethm lgh.

Each pockei thus dischargs its fluid as the cylinder slows down to a tumbling speed. The fluid then enters the shell 534 which may include the apron H a nd it dischargs through the outlet pipe 48, Th] ough valve 43, into the used fluid tank 50 or othi r outlet depending upon the character of the m whine.

The dlspositon of the discharge outlet Ii at the lower portl' on of the pocket 3 of further importance in cl :aring the genes! water level in the shell or cyl nder during extradimr During a tumbling proc :55 any fluid icked up by the pockets will be discharged lludically at once. Cleaning fluid is thrown toward the all or the shell from Whii :h it is drained so that it does not tend to enter the discharge outlet 8. During discharge from the pockets the clllntabalance fluid is isolated from the damp-dried articles by the solid end wall 41 in back of which the fluid The pockets may discharge the counterbalance fluid into theshell by having their floors inclined as disclosed in our previous application. It may further be noted that the fluid instead of being fed through the pipes 29-41 as in the preferred embodiment, may be fed through the rotating trunnion of shaft in the manner disclosed in such previous application. Thus, the fluid may be directly applied to the pocketstbroughboreslnthe trunnionasinthe previous application or it may be transferred fromsuehborestotheteedringsdlsclosed herein prior to its injection into the pockets.

In the embodiment illustrated, the machine takes the general form of a dry cleaning apparatus, although a washing machine will operate critically. If the cylinder is vertical instead of being horizontal as shown, the balancing pockets willalsobeverticaLaswillbeobvious ormaybe horizontally arranged around the base of the cylinder or basket as will be understood from the elongated horizontal cylinder hereinafter dis- As a dry cleaning apparatus, the used fluid tank I receives both the contaminated cleaning fluid as well as the oounterbalancing fluid and foods such combined fluids. usually after filtering. into tank II through pipe 82. Further details of such a system are described in connection with Fig. 16. The filtered or clean fluid is then utilized for further cleaning and counter-balancing operations. As a washing machine, it is evident that water will generally be used for this P 1 6 although any fluid may be employed including mercury, preferably maintaining it isolated from the cleaning fluid.

Pump 53 serves to bring the counterbalancing fluid from tank up through master valve 54. through pipe. 55. to the three solenoid feed valves 26, 21 and 28, wherei'rom it may proceed to the jets 12-34 pursuant to the controlled action of the feed valm. as hereinafter set forth. The provision of master valve 54, operated in one manner as will appear hereinafter, is thought to be desirable in that it adds an additional pre caution against fluid leaking and travelling into pockets apart from the action of the control systern. The use of a pump is considered to be of some advantage since it predetermines the fluid feeding pressure and avoids random rates of fluid flow.

The physical elements of the apparatus. excluding the foregoing details of the counterbalancing system, are generally conventional. Thus, the shell Sla may be provided with hinged door 56 to deposit or remove the articles from the cylinder. Shaft I. being shown as somewhat elongated, may be maintained in two spaced antli'riction bearings 51 and SI which may themselves be suitably supported as desired. The motor II is either a. two-speed motor or one of variable speed, a lowerspeed belng used for tumbling of the articles as during cleaning pro so. while a considerably higher speed is used for the centrifugal extraction operation. If the machine takes the form of an extractor without washing feasuch'lovger speeds may be used for predistribution frmctions in achieving a rough balance prior to the action at the corrective system disclosed.

The electrical operation comprising the control system of the apparatus will now be described. The apparatus applies counter-balancing 8 fluid to selected pockets during acceleration and high speed rotation 01 the cylinder and in re sponse to a specific condition of unbalance. Means are provided to establish the presence of a predetermined degree of unbalance and its l0- cation, and certain corrective measures are there upon automatically put into effect. Means syn chronized with the rotation of the cylinder are utilized to provide a reference voltage by which the instantaneous position of a particular segment of the cylinder may be momentarily established. Thus, the site of unbalance can be located, the presence and degree of which is indicated by a vibration-responsive device, as hereinafter described.

An electrical circuit is provided which reacts to Joint stimuli. one of which is the reference voltage and instantaneously establishes the position of succeaive pockets of the rotating cylinder while the other simultaneously provides an indication of the presence as well as the degree of unbalance. Jointly, they produce a reaction in the circuit which is so timed by the reference voltage that the site of required correction is thereby established. Such reaction i arranged to energize one or more solenoids so as to open one or more associated valves 26, 21 and 28 and thereby introduce counterbalance fluid into selected feed rings and pockets.

In order that the explanation of the electrical circuit be more comprehensible in relation to the operation of the apparatus, the following principles of operation may be noted.

When the overweighted portion or the unbalanced, rotating cylinder passes a predetermined point, the actuating portion of an electrical sig nal is produced. This signal indicates both the presence of unbalance and its degree or ampli-- tude but is of itself insufllcient to permit cor rectlve action to be taken because the site of unbalance is still unknown. To supply the required information, an arm or the like is caused to be driven in synchronism with the cylinder as by being mounted on the shalt l9 and driven thereby. This rotating arm, by commutator action, provides a series of electrical signals as it rotates'each signal indicating or identifying a particular segment of the cylinder. .Accordingly, when the first or vibration signal is emitted, the commutator arm establishes the position of the rotating cylinder at that particular time so that all required information is supplied in electrical form. Both electrical signals are applied to an electrical network which causes selected solenoid valves to operate and automatically inject counterbalance fluid in a pocket or pockets opposite to the site of unbalance. Such injection continues while the overweight becomes neutralized whereupon the vibration slgnal decreases and finally is too small to actuate the electrical network. At such time injection is discontinued. If, as extraction of cleaning fluid from the articles proceeds, sufliclent vibration is again produced due to subsequent unbalance whether ascribable to changes in weight distribution or to greater centrifugal forces generated by successive high speeds of rotation, the actuating vibration signal i re-established and corrective action is automatically re-lnstituted.

In additionto the above functions, the circuits disclosed prevent full speed rotation of the cylinder until a satisfactory degree of balance is achieved. This is accomplished by noting the duration of operation of any solenoid feed valve and intermittently cutting oil the motor I! if such duration exceeds an arbitrary, predetermined time. In other words, if a pocket 01' the cylinder is receiving fluid to correct unbalance, it is undesirable to proceed to higher speed until corrective action is taken since the unbalance may be excessive and cause injury to the machine. Accordingly, the continued operation of the solenoid teed valves is arranged to cause intermittent cessation of motor operation, the circuit further acting to resume constant motor operation and accelerated speeds when the feed valves are no longer injecting fluid for sustained periods.

In order to determine the presence of unbalance, a crystal pick-up 18 or the like may be utilized, as shown in Figs. 2 and 4 and may be supported from the iloor although an alternative support and modified mounting are described hereinai'ter. It'is apparent, however, that any equivalent device such as a magnetic or a strain gauge pick-up may be used as may be an electrical switch as will hereinafter appear. The electrical output of the pick-up, as is well understood, is alternating current of substantially sine wave form produced pursuant to the vibration of the cylinder l1 in a condition of unbalance.

Referring to Fig. 4, the pick-up generates electrical voltages through the action of the crystal 18 and such voltages are applied to the con trol grid 11 of a vacuum tube 1!. Tube 18 is illustrated as being a pentode so as to achieve high gain but it is evident that any amplifying tube may be employed. The condensers and resistors shown in the tube circuit provide conventional grid bias, screen grid voltage and by-l s and control grid leak resistance according to principles which are well understood in the electronic art, and which need not, therefore, be further described. Voltage for plate 18 is secured through wire 80 through plate load resistor 8|. Wire 80 is connected to one side of choke 82 which, as will be recognized from the rectifier 83, is a, positive source of voltage. Rectifier 83 is a conventional full wave rectifier which converts the voltage of transformer M to direct current, the switch 85 applying the alternating voltage to the transformer. The secondary 86 of transformer 84 is employed to ener ize the heaters of the tubes. However, any suitable source of current may be employed.

Vacuum tubes 81 and N are fed by vacuum tube 18 and function to cut oil operation of the apparatus when unbalance exceeds a predeter mined level as will hereinafter be described. Tube 18 feeds the vibrationsignals through coupling condenser 89, wire 80 and wire M to the three valve control vacuum tubes 82, 53 and 34.

Tubes 92, 93 and 94 form part of a valve control system and are illustrated as being gas filled discharge tubes of the thyratron type although.

it will be recognized that many other types of vacuum tubes may be employed. The function of tubes 92-44 is to close the circuit of the electro-magnetic windings 85, 8G and 81 of the feed valves 28, 21 and 28 so as to control the flow of counterbalancing fluid through the pipes 29-3 l. Tubes 82-94 are phase-controlled so as to operate upon a predetermined coincidence of plate and grid voltage. Whereas the grid voltages are supplied through the operation of the pick-up 15, the plate voltages are supplied by a commutator or distributor disc 38 which is maintained stationary in the housing 99 as shown in Fig. 1.

commutator disc 98 (Fig. 4) contains three segments llili, NH and it! which are of electri-' cally conduct ve material and separated by in sulating mati rial. For example, each segment may occupy z bout degrees of a circle while the insulatin: areas occupy about 10 degrees each. COl'lii'Ill itator arm IN is connected to shaft it so as to rc tate therewith and efi'ect consecutive electrical contact with the stationary commutator segrr ents. It is evident, however. that the disc may rotate and the arm may be stationary since only relative rotation is necessary.

Spring-pressed contact I bears against the hub of arm i M and may take the form of a conventional elec ;rical brush. Wire I05 is connected to contact I0 so as to apply thereto the B plus voltage derivei from point I08 of the power supply. As an e: :ample, this may be in the neighborhood of 301) volts. Wires I01, I08 and III! are connected thr Jugh the plate load circuits .to the plates of tube: 82--84. In this manner, the commutator whici makes one revolution for every revolution of ihe cylinder thus acting as a reference multiple switch, successively applies operating plate vo itages to the tubes 91-9| and removes such V1 :ltages as the arm m leaves any one of the se zments.

It will be rwognlzed from the foregoing that any one of thi tubes 82-88 will conduct current according to t ie phase relationship or time coincidence oi the grid and plate voltages. Inasmuch as the voltages applied to each plate are periodically cut 1ft, it may be considered that the plate supplies consist of alternating voltages of square wave form. Since the phase of the grid voltage will dl pend upon the site of unbalance, variations of such site will vary the relative phase of the two voltages on each tube, that is, the relative til me at which they reach their peak values. If the phase of the grid voltage lags the plate voltage 'iy degrees, the plate current will be entirely cut oil. When both the grid and the plate of a1 1y tube are positive, plate current will flow, the aositive value 0! grid current depending upon the firing voltage in the tube as determined by its constants and bias. The same action may be achieved by employing negative grid voltage a; where the de-energization of a tube releases a relay or the like which closes the circuit to an :lectro-magnetic control valve 0! the type disclc sed herein.

Bias for the tubes 92-418 is supplied by potentiometer arn H8 which thereby functions as a sensitivity cc ntrol inasmuch as it sets the level at which the Ci ntrol tubes will operate. In order to provide for i tability of operation, .the grid bias voltage may bi secured from a regulated source of voltage. T his is illustrated as proceeding from dropping resistor H6 which is connected to one side 01' t1 ie high voltage winding of the transformer. Ilesistor H8 is connected to selenium rectifier In which supplies direct current through the re| :ulating resistor H8 to the voltage regulator tube H9. Tube 9 may be .of the type VR'15. Resistor I20 serves to limit the current flow. Arm Iii may be set, for example, to bias the control g1 ids of tubes 9I84 to 20 volts negative deper ding upon the output amplitude of amplifier tube 18 at which corrective action should be takei l.

In order thai tubes 82-94 be not operated by shock generated or transient voltages, a filter condenser I2I may be supplied. This filter condenser is more or less representative of any required type of f lter which may be as elaborate as necessary. FOi example, a two or three stage filter circuit as employed in well filtered power supplies may be used. Condenser I2I may be in the order of .01 microfarads. Shock voltages are generally of high frequency whereas the signal voltages applied to the grids are in the neighborhood of 15 cycles per second or less so that the filter condensers I2I may be rendered eifective in grounding the undesired shock voltages while having relatively little effect on the desired signal voltages.

As heretofore explained, arm I02, being keyed to the shaft It, constantly maintains an angular .position, which is related to the angular positions of the pockets 2I, 22 and 23, or to the segments of the cylinder which they represent. Accordingly, because the cylinder and pockets turn with the shaft as does the arm I03, the time of application of the plate voltages to tubes 92l4 will establish the momentary position of such pockets or segments. Such establishment of the angular position of the pockets is combined, as aforesaid. with the amplitude of unbalance voltage so as to cause the counterbalance fluid to fiow to the required pockets.

Referring to Fig. 6, the square wave I25 may represent the plate voltage on tube 92, the duration of such application of plate voltage depending upon the arcuate length of the segment I00 of the commutator disc. As arm I03 leaves segment I00, the square wave terminates and approximately 10 degrees later the voltage is applied as square wave I26 to the plate of tube 94. In the same manner, square wave I2I is thereafter applied to tube 93 through segment I02. The cycle thereupon repeats itself as illustrated in Fig. 6. Each square wave represents a pocket of the cylinder and the waves repeat in the order of l, 2, 3, 1, 2, 3, etc. Thus, a continuous seriesof pocket or segment identifying signals is provided in cyclical form as the cylinder rotates.

At the same time the plate voltages are successively applied to the three tubes in any one cycle, the pick-u voltage I2l'which is generally of sine wave form, is applied to the control grids. If the crest I29 of the sine wave is applied to the grid during the same period 01' time that square waves I26 and I21 are applied to the plates of tubes 53 and 94, then both tubes 92 and 94 will fire and will open their associated valves so as to supply counterbalance fluid to two of the pockets, such pockets being 22 and 22. It will be evident that if the crest I29 were to be advanced a few degrees because of a shifting of the overweight, only tube 83 would be actuated and only its associated pocket would be fed. Fig. 6 illustrates the fact that two pockets may be fed simultaneously pursuant to a specific state of unbalance. This is of considerable importance as 0therwise the filling of one pocket at a time causes delay and prolongs balancing operations whereas filling of two pockets in certain cases prevents such occurrences by takingcare of most sites of unbalance simultaneously.

The firing voltage I30 depends upon the setting of the sensitivity control 5. Any of the tubes 02--94 will fire when the voltage on the grid exceeds such firing voltage while the plate voltage is applied. The tubes 92-94 control the operation of valves 2i-2l in the following manner:

Assuming that commutator arm I03 is in contact with segment I00 so that tube 92 is provided with plate voltage and assuming further that at that very time the grid voltage amplitude reaches the firing voltage, tube 92 will become conductive. Considerable plate current will fiow through tube i2 92 so as to energize relay I35. Armature I38 will thereupon be drawn inwardly so as to close contacts I31 and I30.

Electromagnet winding 95 (Fig. 4) will be energized through wires I39 and I40 connected to the primary or power transformer 84. It will be understood that electromagnet 95 is a winding of a conventional A. C.-operated solenoid valve 25. At this point, fluid from pipe 55, Fig. 1, will be supplied to pipe 29, Jet 32, feed ring 35, and pipe 36, into pocket 2I. The fiuid will therefore be correctly applied so that the cylinder approaches a state of balance. As the counterbalance fiuid pours into the pocket, the amplitude of the grid voltage will decrease as the vibration decreases pursuant to the correction of unbalance. When the amplitude is such as to descend below the firing voltage I30, tube 92 will extinguish notwithstanding the coincidence of the plate and grid voltages. It is a recognized characteristic of gasfilled tubes of the thyratron type that removal of grid firing voltage alone does not per se produce tube extinction. However, the described method of removing the plate voltage by the commutator action insures proper extinction of the tube since it is well known that the absence 01' plate voltage will produce this efi'ect.

If ordinary vacuum tubes of the power amplifier type are employed, the plate voltage may be continuous and constant, while the phase of the grid voltage will determine the particular tube or tubes which will conduct current so as to operate the solenoid valves, as set forth in our abovementioned previous application.

The comrmitator segments are generally spaced approximately 10 degrees apart in order to decrease the angular sensitivity of the system so as to avoid overcompensation when the unbalance is slightly displaced from a position opposite a pocket. Referring to Fig. 6, it will be evident that if the crest of the grid voltage were shifted slight 1y from time coincidence with one square wave to another, the margin or pacing provided between the successive square waves prevents corrective action so that the angular sensitivity is decreased. It has been found, in fact, that 30 degree commutator segments separated by degree areas is satisfactory. The tubes 93 and 84 function in the same manner as tube 92, and one or two of the tubes, but not all of them, may function simultaneously as will be observed in Fig. 6.

Inasmuch as the relay I35 is operated only when a pocket is being filled, it affords means to provide visual evidence of the operation of the balancing system. Accordingly, an armature I 45 is provided which, upon closing contacts I46 and I41, provides energizing potential for pilot light I48 through the transformer secondary 86.

A modification, not shown, of the electronic control unit which employs but one thyratron tube, instead of the three shown in Fig. 4, is feasible and has apparent advantages. Thus, the leads to the plates of tubes 92, 93 and 94 are tied together and are connected to the plate of the one thyratron tube. The control grid of the tube is connected to the coupling condenser 89 while the cathode is connected to ground in the usual manner. This substantially completes the circuit in combination with the remainder disclosed.

In order to insure complete de-ionization of the tube before the brush starts commutation on the succeeding segment after the tube has been fired, it is necessary that the segment insulating areas or air gaps be greater than the brush width by an amount suiliciently large to insure interrup- 13 tion 01' the plate voltage for the de-ionization time o! the thyratron, as will be evident to' those skilled in the art.

The electrical components above described are maintained in a housing I45 which may be disposed on ,the shell or housing 50A. The three lamps or pilot lights I48, I50 and 1H will light according to which of the pockets is being filled at any particular time.

Since the tubes will successively extinguish as the commutator arm rotates, under ordinary conditions the valves would be de-actuated between firing periods so that counterbalance fluid would only flow when the tube was firing and, therefore, would flow in spurts. that is, the'control valves would open only once for each revolution of the cylinder, and in addition might chatter and wear excessively. It is important to avoid such periodic action and to maintain a continuous flow and means are therefore provided to continue the action of the solenoids !or a period after the tube associated therewith has been extinguished and at least until the tube re-fires when the plate voltage is resapplied thereto.

This is accomplished by providing holdover circuits in the form of condensers I55, I55 and I51 eiiectively disposed across the respective relay windings. The commutator action will charge each condenser at the same time that the plate voltage is applied to the tube associated therewith so as to fire the tube. when the source of voltage is removed, the condenser will maintain energization of the relay by discharging therethrough. The capacity of condensers I55, I55 and I 61 is chosen so as to produce a time constant network which is correlated with the lowest speed of cylinder rotation at which balance is desired. It is apparent that i! the cylinder rotates. times a second at minimum extraction speed, for example, the time constant may be in the order of one-filth of a second and the holdover circuit elements will be selected according to well known standards. By this means, when the correct pocket or pockets have been established for the introduction of counterbalance material, the application of such material will be continued to such pocket until balance is achieved notwithstanding the periodic extinction of the tube which controls the valve. Resistors 150 and IGI are current limiting resistors which may have approximate values of 5000 ohms and ohms respectively. The time constant may be set to correspond to the lowest speed of extraction operation at which balance is desired. However, if it is desired to render the time constant somewhat proportional to rotation speed, the resistor Hii may be increased to 1500 ohms or so, so that the condenser charges less at high speeds since the arm I03 passes the commutator segments more swiftly and condenser is thus given lesstime to charge; accordingly, its hold-over time will be correspondingly less. It is also feasible to employ dash pots built into the cores of the relays so as to produce a mechanical or hydraulic delay of the closing of the control valves.

Although a cylinder having three pockets has been shown, it will be obvious that many more such pockets may be provided if finer degrees of balance are to be achieved. In such cases. the commutator would be provided with contacting segments of a number commensurate with the division of the number of pockets into 360 degrees, as will be evident.

Means are provided to discontinue operation 01' the cylinder when the unbalance is so great as to be potentially injurious to the machine. For this purpose, the on put of amplifier tube 18 '18 caused to shut oil? ti e motor when such output exceeds a predetermined level. The output of tube 18 is applied th'ough condensor M5 to rectifier tube 81. The output of tube 81 is essentially an automatic v )lume control circuit, as will be evident. Howevei it is not used as such but serves to apply a con urol voltage to tube 88. P0- tentiometer arm I66 is set according to the level at which operation should be discontinued. Normally, tube 88 will be passing current and the electromagnet I51 which is in its plate circuit attracts armature I5 I so as to maintain the contacts I59 and I10 nor mally closed. Thus. the extractor motor canno; be started until the tubes of the electronic un t have heated to operating temperatures. Upor. a 'high amplitude signal from rectifier 81, tub: 88 is cut off and armature I68 is released. Coni acts i8! and I10 which normally maintain term .nals C and D closed, thereupon open the circuit and cut of! operation of the motor, as will be i iescribed in connection with Fig. 5.

The instant invenzion comprehends the provision of a motor control circuit which serves to render the aforedesci ibed balancing system more eifective. A primary feature in such motor control circuit is to disable motor operation intermittently during pro longed periods of balancing through fluid lniectil n. Inasmuch as the motor, or a clutch rotates th a cylinder at extremely high speeds, it would not i e desirable to permit unrestricted acceleration during a marked degree of unbalance even whi e such unbalance is being corrected. This, as well as other improvements in the operation of ;he system are provided by the control circuit ill istrated in Fig. 5.

Terminals A and ii shown in Fig. 5 are connected to theccorreslrondingly lettered terminals of Fig. 4, while the ierminals C and D are likewise connected to the C and D terminals of Fig. 4. Motor i8 is disclosed as a three phase motor operated through th lines 200, 20! and 202 The components shown tnclosed in the broken line area 203 are those of a conventional magnetic starter for electric motors. In order to adapt such a starter to the required operation of the instant apparatus, wires 204 and 205 of the mag netic starter are briken and the armature or contact 206 of time delay relay 201 is inserted thereat. Wires 208 and 209 are provided with a push button starti' 1g switch 2i0 which is nor mally in the open pi sition shown. Winding 2H is the conventional moi] of the magnetic starter which normally ma ntains armatures 2l2-2i 5 open. When winding 2 is energized, pursuant to the conventional action of such magnetic starters, these armatures close the circuit and permit operation of the motor I8 through the three phase lines. lieaters 2H; and 2H operate the thermo-switches 2|! and IIS respectively so as to provide thermal overload circuits for cutting off the motor under conditions of a short circuit or the like.

Switch 220 is a stop switch which is normally closed and permits the apparatus to be shut oil at the will of the o1 ierator. Relay winding 22! having armatures 22l-224 is provided to maintain a closed circuit 1 or time delay relay 201 when any control tube of Fig. i is operating a feed valve, as will be her :inafter set forth. The following describes the operation of the motor control circuit, it being presumed that the electronic unit, schematically illustrated in Fig. 4, and

housed in the case I49 (Figs. 1 and 2) is in operation.

Referring to Fig. 4, when winding I35 is energized indicating that feed valve 26 is operating and pocket 2| is being filled, relay contacts 230 and HI close. This shorts the terminals A and B so as to close the A B circuit. The same action results when any of the other control tubes are operating, so that A and B are shorted during the filling of any pocket.

Referring now to Fig. 5, terminals C and D are normally closed as above stated, and only open under such large degrees of vibration as warrant shutting oil the motor and re-distributing the articles; 'fli'hus, C D may be considered to' be closedd-uring conventional operation.

Lines aiid=2ii2 of the-three phase lines provide' operating voltages for the motor control relays above described. Accordingly, when the normally open start switch 2|0 is manually depressed. as when the machine is put in operation, the operating current will travel from line 202 across C, D, the normally closed stop switch 220, the switch 2 Hi, the normally closed armature 206, and across the thermal switches to line 20L Consequent energization of winding 2 draws its four armatures inwardly so as to close the motor circuit and operate the apparatus.

Closing of start switch 2!!! also energize relay winding 22l which remains locked through closed armature 2I5. Such operation of winding 22l closes armatures 222, 223 and 224, so as to permit time delay relay 201 as well as master valve 54 to be energized upon closing of the A, B circuit. In addition, solenoid winding 226, which is a solenoid operated friction brake against the shaft I9, is also energized. Such friction brake is operative in the absence of energizing current, but energization of the winding, as by closing the start switch, withdraws the brake. This action is conventional and forms no part of the instant invention.

Time delay relay 201 is provided to achieve intermittent operation of motor [8 during times when the pockets are being filled. As above stated, it is desirable to avoid full speed operation of the motor under a marked condition of unbalance in order to avoid excessive vibration, personal danger. and possible damage to the apparatus. This objective has been realized by interrupting operation of the motor if any control tube 9294, or combination of control tubes, operates for more than a predetermined time, for example, three seconds. If the three second interval during which the control tube operates is .insufllcient to fill a pocket to balance requirements, the time delay relay 201 opens the motor circuit until the control tubes extinguish. If an external source of fluid is being used, as, for example, the municipal water supply at its own pressure, the motor may thus be cut-oil more or less frequently and may coast for longer or shorter periods, depending upon the pressure. and, therefore, the rate at which the pockets are being filled. Such operation is valuable as a safety measure inasmuch as variations in fluid feeding pressure cannot affect the expedient of avoiding motor speed-up while unbalance is present. It will be noted that the balancing operations occur principall at speeds less than full speed or during acceleration of the motor. When the cylinder has attained full speed rotation, only small amounts of counterbalance fluid will be required to maintain such balance as the 16 cleaning fluid is extracted from the articles and, therefore, changes the weight distribution.

It is necessary, in the form being described, that when the control tubes extinguish and terminals A, 13 open, the time delay relay 201 must automatically reinstitute operation of the motor. Accordingly, the action thereof is to be distinguished from the action of the stop switch 220 which cuts of! motor operation so that it can only be reinstituted by manual operation of start switch 220. The disclosed time delay circuit accomplishes the automatic intermittent starting of motor [8 whereas the normal action of the magnetic starter is to cut off the motor until the operator puts it back in operation by manually actuating the start switch.

Relay 207 is of a conventional type having a three second time delay in operation and a substantially immediate reset time. When terminals A. B are shorted; indicating the presence and correction of unbalance, the time delay relay, after a, three second interval, opens'armature 206 so as to de-energize coil 2| I, and open the circuit to the motor and discontinue its operation. Helay winding 22| remains closed, however, so as to maintain the time delay relay circuit and the brake circuit likewise closed. When the control tube extinguishes, and terminals A, B open, the time delay relay 20! becomes de-energized and armature 206 returns to its normally closed position, re-energizing the magnetic starter coil 2H and re-instituting motor operation automatically.

With the provision of the foregoing motor control circuit, each control tube operates in normal fashion, but the motor l8 cannot bring the cylinder up to full speed during such a condition of unbalance as requires more than three seconds of continuous counterbalance fluid feeding time. Inasmuch as three seconds is not suflicient time for the motor to rise to full speed, unbalanced full speed operation is prevented. The motor cuts in and out automatically according to the operation of the control tubes although the stop switch 220 is nevertheless operative in its normal manner to discontinue operation of the motor without danger of its automatically starting because of the time delay circuit disclosed. The three second interval is, of course, variable over a very wide range depending upon the size of the feed valves and the degree of pressure in feeding the fluid as well as the size of the machine.

It will be understood that the time delay relay takes effect many times during the extraction operation as the speed increases or as the balance varies through extraction of fluid. For example, a condition of unbalance at one speed may be corrected for that one speed but as the speed increases that same condition may re-actuate the balancing elements because of the increase of centrifugal forces or the effective re-distribution of the weight within the cylinder through the varying losses of fluid in the soaked articles.

Valve 54 which is in the supply pipe line as disclosed in Fig. 1, closes when terminals A, B are shorted so that said valve is open when any of the solenoid valves 2628 are open and it closes when one of those valves is closed. This expedient is provided in the event that any of the closed control valves leak, such leakage being guarded against by the precaution of maintaining valve 54 closed at that time. If a pump is used tosigply the fluid pressure, its motor may take the place of valve 54 so as to be operated in like manner as explained hereinafter.

amazes The above apparatus provides a balancing system for extractors per se or in either washing or dry cleaning machines or the like which may include a tumbling operation and which effect extremely high speed operation of the rotating cylinder so as to realize the advantages of high speed extraction generally set forth above. Due to the balancing action of the apparatus, substantially higher speeds are feasible while the installation of a machine of this type is facilitated and elaborate mountings in floor supports are unnecessary.

Figure 7 illustrates a machine generally similar to that of the foregoing flgures and applicable toward the correcting of dynamic unbalance in an elongated double bearing machine. The balancing system is applied at both ends of the elongated cylinder rather than to one end. Other modifications are likewise disclosed.

In Fig. 'l, the cylinder 250 is rotatably housed in a stationary shell L The cylinder is rotated by its trunnions 252 which are actuated by a. driving motor. not shown, and rotate in antiiriction bearings 25!. Each end of the shell 2H has separate and independently operating pickups 254 and 255. The action of the pick-up 2 determines the flow of counter-balance fluid through the feed ring assembly 256 in the same manner as shown in Fig. 1. Thus, the feed pipe 251 functions as does pipe 29 while other pipes feed the other feed rings. Each teed ring is further provided with a feed pipe 258.

The cylinder 250 is provided with two end sets of outside elongated pockets, each set consisting of three in the form shown. Referring to Fig. 8, the three pockets 250, 26], and 252 are angularly disposed around the outside of the cylinder in equally spaced relationship. Pocket 260 receives the counterbalance fluid from pipe 258 through chamber 264. Chambers 264, 265 and 266 in the aggregate occupy substantially the entire circumference of cylinder 250. Each chamber communicates with its associated pocket and is separated from the other chambers by partitions 261. The floors 26B of the chambers terminate short oi the partitions so as to provide a discharge outlet for counterbalance fluid after the extraction is terminated and the rotation speed of the cylinder materially decreases. The chambers extend to the periphery of the cylinder and counterbalance fiuid will be initially diirected toward such periphery by centrifugal force. Thus, the chambers are effectively disposed adjacent angularl spaced peripheral portions of the cylinder as are the elon ated pockets.

According to a specific state of unbalance, as determined by a commutator such as commutator 98 of the previous embodiment, in cooperation with the pick-up, counterbalance fluid will flow through pipe 258 and into chamber 264. Centrifugal force generated by the rotation of the cylinder will impel the fluid away from the axis of rotation and against the periphery of chamber 284 so that the fluid will tend to spread laterally against such periphery. Accordingly, the fluid will flll the pocket 260 as it spreads from the chamber 26. This provision of endwise disposed chambers ls considered to be of advantage in that a large amount of counterbalance fluid -may be applied so as to accommodate large dechambers are used as hereinafter described, the

effect of added weight at one end is minimized in regard to ihe other end. Each feed ring assembly 286 at each end of the cylinder may feed one or two of ts chambers and hollow ribs in the same general manner as in the flrst embodiment described. In order to isolate respective end pockets or ril s fromeach other when they are used, they ten ninate in rear walls 269 and an intermediate area 210 does not receive counterbalance fluid. This space 210 is variable and may be of grc ater length so as to maintain the balancing fluid as close to the bearing 253 as will permit an d still provide extra space for balancing fluid :or very large amounts of out 01 balance to be corrected. The elongated pockets, may, if desire i, be dispensed with and only the endwise chambers be employed as weight receiving elements.

As cylinder rotation decreases at the end of an extraction operation, and centrifugal forces no longer mai atain the fluid against the ceilings of the chambe rs and pockets, the counterbalance fluid will flow out of such pockets and chambers through the d scharge outlets 21! formed by the openings in fl ors 268. Such discharging fluid will reach the shell 251 where it may be further discharged or fed through the valve 212.

It will be understood that only one commutator in the n: iture' of commutator 88 will be required for bo'h ends of the cylinder and such commutator may be disposed on either of the shafts or trui nions 252. The electrical circuit for each end of the cylinder will substantially duplicate tha; disclosed in Fig. 4. The door 213, it will be recognized, is provided so that the cylinder may be loaded with or emptied of articles.

Fig. 9 illus' rates a modified embodiment of each end of tt e elongated cylinder shown in Fig. 7. The chamber 215 is separated from its associated poclnt 216 by a, wall 211. Accordingly, fluid from feed pipe 218 first fllls the chamber 215 in oriier to correct a condition of unbalance. If chamber 215 is of insufllcient volume to eflect lueh correction, the fluid will further feed thr )ugh pipe 219 and through wall 211 into pocint 218. Pipe 280 is provided as an air outlet for pocket 216. Should chamber 216 be of sufilciet 1t size for all general purposes, pipe 219 may be closed or omitted and all bal- 'ancing fluid v ill therefore remain closer to the end bearings. In any event, the fluid receiving pockets may t: he the form of angularly arranged end chambers such as chamber 215 without including elongs ted pockets as above noted. Pipes 219 and 280 m 1y also be water outlets.

Figures 10 a nd 11 disclose a modified form of pick-up arrangement which is particularly useful with the a pparatus of the instant invention. Bearings :00 and 3M substantially duplicate bearings 51 and 58 shown'in Fig. 1, shaft 302 duplicating sh aft IS. A crystal pick-up er snap switch or the Iike III! is mounted on support 304 integral with bearing Illl. An arm 305 is connected to plai form 306 which supports bearing "I. Bracing arm 301 may also be provided to effect further mechanical support for arm 305.

assaaea 19 mounted on the machine itself instead of being mounted on the floor as shown in Fig. 2. The cylinder attached to shaft 302 is rigidly supported in its bearings and represents an overhanging weight. The shaft, being somewhat elongated, will rock about a central point in a see-saw movement produced by uneven distribution of articles in the rotating cylinder. Thus,

one end of the shaft 302 will have a component of movement opposite to the other end thereof. One end of the arm 30! is connected adjacent to one end of shaft 302 nearest the cylinder as shown although it may be attached to the shaft itself. Arm 305 is thereby caused to partake of the same movement as that portion of the shaft while the pick-up 303 partakes of the movement of the other end of the shaft. Accordingly, substantial relative movement is created between the arm 305 and pick-up 303 notwithstanding the fact that they are mounted on the same base, and such movement produces the plckrup signals through displacement of the crystal pick-up pin or microswitch button.

Bearing 30! is rigidly supported on platform 3 which is braced by arms 3 on standard 3l2. Standard 312 may be a. vertical steel column without side braces so as not to unduly resist relative movement of the outer end of shaft 302 and permit a slight horizontal movement generated through cylinder unbalance, as above described. Tank 3i3, serving as a base, is similar to tank 5! of Fig. 2 while structure 3 ll may be the shell of the machine.

It is to be noted that the vibration pick-up action may be accomplished with a microswitch or snap switch instead of a crystal, the microswitch operating from the deflections of the bearings and functioning to make and break the electrical circuit as disclosed in Fig. 14 Thus, such a microswitch performs the required function of supplying vibration voltages without the use of vacuum tubes or similar amplification means.

Figs. 12 and 13 disclose a further modified form of pick-up arrangement in combination with variations in the physical structure of the apparatus but the form of the pick-up arrangement is not claimed herein, although the physical arrangement of the pockets and chambers is included in the instant invention. Shell 325 is supported on base 326 and is provided with a dump valve 321. Standard 323 supports hollow trunnion 328 through anti-friction bearings 33!] and 33L Trunnion 329 is supported on end wall 332 of the cylinder 333. Such support is rendered slightly resilient or yieldable through the medium of a rubber pad or gasket 334 interposed between the annular flange 335 of the trunnion and the end wall 332. Rivets 336 maintain the required connection By this'expedient, the trunnion 329 is permitted a wider range of relative -movement in response to vibrations of the cylinder; Rod 33! is connected to end wall 332 as by the rivet head 338 so that the rod 331 partakes of the movement or vibration of the cylinder. A pick-up 339 is disposed at the outer end of rod 331 so that variations of vibration between the trunnion or bearings and the rod are applied in physically amplified form to the pick-up although such amplitude may be regulated as described by varying the resiliency of the gasket 33. A commutator (not shown) may be employed as in the previous embodiments, so that conditions of unbalance will be corrected through the system described herein.

The feed ring assembly 340 takes the same form as in the previous embodiments with, however, slight modifications in the form of the feed pipes and pockets. Thus, the feed pipe 3 ex tends into pocket 342 through auxiliary chamber 343 having an outlet discharge of the fluid after the extraction operation. Thus, a short outlet pipe I further directs the discharged fluid into the shell and it effectively extends the pocket or chamber opening so far to the center of the cylinder that the entrance of cleaning fluid into the pocket during tumbling and washing operations is particularly minimized.

It is evident that such undesired flow, if any, would occur principally when a guide pipe had 1% mouth somewhat upwardly disposed, as when it is passing along the floor of the shell. At this time fluid might be scooped into the guide pipes and to the pockets. Accordingly, and for further assurance, it is contemplated that a conventional gravity actuated ball valve (not shown) may be enclosed in a retaining wire guard over a beveled or conical mouth of each guide pipe so as to seal such mouth when it is upwardly disposed and to fall away therefrom so as to permit discharge when the mouth is above the center of the shell.

In Fig. 14 is disclosed a modification of the electronic circuits of Fig. 4. An apparatus incorporating the circuit of Fig. 14 is particularly well adapted for household uses in that it is more simply manufactured, is less expensive, and will nevertheless be entirely satisfactory for general requirements. Shaft 350 is the driving shaft for the cylinder and corresponds to shaft [9 of the first embodiment. commutator 35l sub stantially duplicates commutator 93 of such first embodiment (Fig. l). Actuating power for the relays originates at the terminals 352 and 353 and is rectified, if desired, at 354. The rectified current is fed through current limiting resistor 355 to spring arm 356 of a microswitch 351. The term microswitch as used in the electrical art generally refers to a snap switch which is spring-biased to either open or closed position and which is actuated by an outside force, usually mechanical. In most such switches, the force required is rather minute, depending upon the specific application.

Arm 358 is connected to switch arm 358 as part of the microswitch and is disposed adjacent to either the driving shaft, the shell or the rotating cylinder so as to be actuated thereby when the cylinder is rotating in a condition of unbalance. Such arm produces the mechanical force required to close switch arm 356 against terminal 359. It will be recognized, therefore, that switch 351 takes the place of a pick-up such as employed in the previous embodiment. It performs the same function, that of providing a. vibration voltage, but such voltage originates from the source of supply represented by terminals 352, 353 instead of being generated through its inherent characteristics as does the pick-up. When the cylinder is unbalanced, it rotates eccentrically and the furthest points of eccentricity, whether of the shell, the cylinder, or machine itself, serves to. actuate operating arm 35B and switch arm 356 so as to close the switch. The time then, when the switch closes, determines the site of unbalance.

Shaft 350 has the commutator arm 360 connected thereto so as to eifect successive electrical contact with the three segments 36L 3G2 and 363. Switch terminal 333 is connected to spring contact arm or brush 384 so as to transmit the volt- 21 age to the commutator arm when operating arm 388 is actuated. The source voltage is thereupon ,applied to wires 365, 300 and Iii-respectively.

Wire 105 is connected to eiectro-magnet windin 36!, the other end of which is connected to terminal 352. Accordingly, the source voltage energizes winding 060 when commutator arm 300 is on segment I! at the same time that arm 8 is actuated. Wires 086 and 061 respectively function to close similar circuits to windings I80 and 310 when am 860 makes contactwith segments 38! and 061 respectively. when winding IE is energized, it attracts armature Ill so as to bring contacts 112 and 110 together. Solenoid valve 260 is thereupon energized and counterbalancing fluid is thus caused to flow into its associated pocket. It is possible ior economy purposes, to eliminate the windings 360,008 and 01-0 and actuate the solenoid valve windings directly providing hold-over elements in such valve windings (in the same manner as shown for the relays) as will be evident to those skilled in the art.

It will be recognized that the microswitch, in combination with the commutator forms an electrical circuit such as is formed through the electronic circuit disclosed in Fig. 4. Inasmuch as the time of the closing of the microswitch 051 must be correlated to the action of commutator III, the phases of operation of these components determine the pocket or pockets into which counterbalance fluid is applied. As in such electronic apparatus, it is the coincidence of unbalance reaction as applied through the vibration responsive device and the commutator action which jointly close the electrical circuit so as to energize an appropriate solenoid valve when conditions so indicate.

Each electromagnet winding includes relay contacts such as contacts 314 and 315. These duplicate the function of contacts 230, 231 (Fig. 4) in closing the A, B circuit for the time delay relay 201 (Fig. 5). The electrical circuit of Fig. 14 is used in combination with the Ieed rings, jets and other physical elements described in the previous embodiments.

In order to insure reasonable speed and continuity in the balancing process, each electromagnet winding in Fig. 14 is'supplied with a hold-over circuit designed to continue the application of counterbalancing fluid to the correct pocket notwithstanding the fact that coincidence m tains a flow of current through electromagnetic winding Ill when the voltage directly energizing winding 381 is interrupted. Winding 880, which may consist i ii 1 or-2 turns, is wound on the same core as is winding 3H and it performs in the nature 0! wk. at is known in the art as a shading coil. When 1 he voltage energizin winding "I is interrupted, Winding "0' tends to maintain the flow so that contacts I82 and 383 will be held closed atter vinding "I has been" energized and the commute tor arm has left the segment associated with tl .e winding.

'In order tr provide means for shutting on the motor under conditions of excessive vibration, an additional mcroswitch is provided as shown in the circuit 11 Fig. 14, The microswitch actuat- 1118 member 449 whether the driving shaft, the shell or the :ylinder is caused to act against a second micro iwitch 384 under such excessive derees of vibration. Am 368 of microswitoh 051 is separated from member 349 by a space 185 which represants that predetermined degree of vibration wl rich is conveniently correctablev Space 006, between member 340 and arm 381 oi microswitch J04, is larger and represents such degree of vibration as warrants discontinuing motor operatf on. Accordingly, when this degree of vibration is encountered, mfcroswltch 384 will open so as tc open the C D circuit. Thus, the circuit of Fig 14 may be combined as indicated with the circu its of Figs. 5 or 5A.

In Fig. 16 is d'sclosed an apparatus generally similar to th: t shown in Fig. 1 but adding further details which are generally found in drycleaning appa ratus. Thus. the cylinder, shell and counterbalanc e fluid feeding system are the same as that ShOWI. in Fig. 1. However, the complete system diSOlOiBd in Fig. 16 emphasizes the commen use of cleanin fluid for both cleaning the articles and supplying the required counterbalance weight.

of unbalance reaction and reference action cannot occur when the commutator arm has left a segment which represents the site of desired correction.

The hold-over action thus substantially duplicates the hold-over circuit of the previous embodiments. The hold-over of Fig. 14 is accomplished by providing condensers such as condenser 316 across the winding 060. It will be evident that the inductance of winding 350 and the capacitance of condenser I15 create a time constant network which maintains current flowing in winding 360 for the duration of such time constant. The particular time constant will depend upon cylinder rotation as in the previous embodiment, a cylinder rotating 6 times a second, for example, requiring a time constant of at least V; of a second. Condensers 311 and 318 perform identical functions as condensers 315.

In Fig. 15 is disclosed a modified embodiment of a hold-over circuit which may be employed in any of the previous hold-over networks. In place of a shunting condenser or resistance, there is provided a short-cireuited windin 880 which main- Tank 400, zorresponding to tank 51, contains a supply of cleaning fluid which is drawn up through pipes 40| and 402 through the ncticz. of pump 403. From pipe 402,'the counterbalance fluid is appliei to the feed'rings and pockets pursuant to the c ontrol system heretofore disclosed A fllter-mechs nism and tank 404 is arranged to communicate vith tank 400 through pipe 405 by opening valve i05A and closing valve 408A. Tank 404 may then supply fresh cleaning fluid to the shell 400 through the pipes 40! and 408, valve 400A being tl en opened and valve 405A being closed.

Pipe 40!, in luding the valve 410, serve to discharge used or contaminated synthetic fluid from the shell into the tank 4 from where it is pumped by pump 4|! through pipe 3 into the filter 404. Pi 1e 4" is the usual overflow pipe used to dischs rge any excess fluid directly into the tank 4| I. A pipe H5 and valve 4H5 are provided so as to 1 iermit an interchange between the fluid in tank 4 H and that of tank 400,'when desired. It wil be understood, therefore, that the cleaning fluid 1 nay be used as the balancing fluid originating as "hey do from common sources and flowing through common lanes of supp y and discharge.

As an alter iative 'method of employing the master valve II, a relatively small by-pass pipe 425 (Fig. 16) i: further disclosed as shunting the master valve lut is not claimed in the present application. '1 his construction may be employed in conjunction with the circuit of Fig. 5A. As noted in Fig. 5, i, an armature 42 6, controlled by 

